PRENYL ALCOHOL SOURCE FOR ODORANTS IN ROASTED COFFEE

The identification and characterization of the sulfur-containing flavor components 3-methyl-2-butene-1-thiol, 3-mercapto-3-methylbutanol, and 3-mercapto-3-methylbutyl formate are described. The volatiles were isolated by simultaneous distillation/extraction. After preseparation by means of column chromatography, preparative HPLC, and GC, the aroma extracts were investigated by capillary GC, GC-MS, and simultaneous GC/sniffing. Identification was carried out by retention and spectroscopic data. The proposed structures were confirmed by synthesis. The results of sensory trials indicate that these components may contribute to the flavor of roasted coffee. As the identified components are very likely to be related to each other by their common precursor prenyl alcohol (3-methyl-2-buten-1-ol), the formation pathway was investigated by means of model reactions.